Abstract: An apparatus for cleaning a substrate. A cleaning chamber contacts the substrate with a cleaning solution. The cleaning solution thereby removes contaminants from the substrate and additionally leaches material from the substrate. A gettering chamber receives the cleaning solution, and includes a surface for chemically attracting the leached material and precipitating the leached material at least in part out of the cleaning solution. By removing the leached copper from the cleaning solution In this manner, the various embodiments of the present invention reduce the amount of copper that is available for plating out of the solvent, and therefore reduces the number and size of nodules that can form on the substrate. Thus, the need for other expensive approaches, like chemical replacement or less effective cleaning solvents, is obviated.

Abstract: A method of determining a cost effective number of corrective tests to perform on a process experiencing process excursions. A test cost for each corrective test is determined, and a total test cost for each of an incremental number of corrective tests is calculated. An effect of each corrective test on a reduction in the process excursions is determined, as is also the lost revenue for each process excursion. A reduction in the lost revenue for each of the incremental number of corrective tests is calculated, based at least in part on the effect of each corrective test on the reduction in process excursions and the revenue lost for each process excursion. An overall cost for each of the incremental number of corrective tests is calculated, based at least in part on a sum of the total test cost and the reduction in the lost revenue for each of the incremental number of corrective tests.